基于FPGA和程控滤波的非接触式电流检测装置

基于FPGA和程控滤波的非接触式电流检测装置(论文16000字)
摘要：针对现有谐波电流检测装置成本高、采样噪声大等问题，提出了一种基于FPGA和程控滤波的非接触式电流检测装置。装置由谐波电流信号产生、电流互感线圈、电流-电压转换、程控滤波、有效值转换、精密和高速ADC、电压比较、主控制器等电路模块组成。利用任意波发生器产生一个包含多次谐波的电压信号，经过功率放大电路和负载电阻后，得到被测谐波电流。设计电流互感器实现谐波电流回路与测量电路的非接触式传递，分别采用两种方法测量谐波成分，一是利用程控滤波器分离谐波，并结合精密ADC和等精度测量技术实现；二是利用FPGA平台，结合高速ADC和FFT技术实现。设计并调试了电路，实验测试表明，装置可测量的基波频率范围为50Hz~200Hz，谐波测量次数可达到7次，基波和谐波的电流峰峰值范围为10mA~1A。将测量值与任意波发生器的设置值进行了比对，分析了两种测量模式的误差来源。论文提出的方法和装置可应用到电力系统的电能分析、漏电流检测或其它仪器仪表电路中。
关键词：谐波电流；非接触式测量；程控滤波；FPGA；FFT;

Non-contact current detecting device based on FPGA and program-controlled filters
Abstract: Aiming at the problems of high cost and large sampling noise of existing harmonic current detecting devices, a non-contact current detecting device based on FPGA and programmable filter is proposed. The device is composed of harmonic current signal generator, current mutual inductance coil, current-voltage conversion, programmable filters, RMS conversion, precision and high speed ADC, Voltage comparator, main controller and other circuit modules. The arbitrary wave generator is used to generate a voltage signal containing multiple harmonics, and after passing through the power amplifier and the load resistor, the measured harmonic current is obtained. The current transformer is designed to realize the non-contact transmission of the harmonic current loop and the measurement circuit. Two methods are used to measure the harmonic components. The first is to separate the harmonics by using the programmable filter, and combine it with the precision ADC and the equal precision measurement technology. The second is realized by using FPGA platform combined with high speed ADC and FFT technology. The circuit was designed and debugged. The experimental results show that the fundamental frequency range of the device can be measured from 50Hz to 200Hz, the device can measure seventh harmonic current, and the peak and peak currents of the fundamental wave and harmonics range from 10mA to 1A. The measured values are compared with the set values of the arbitrary wave generators, and the sources of error of the two measurement modes are analyzed. The method and device proposed in the paper can be applied to power analysis, leakage current detection or other instrumentation circuits of power systems.
Key words: Harmonic current; non-contact measurement; program-controlled filters; FPGA; FFT;
 

目 录
1    绪论    1
1.1    研究的目的和意义    1
1.2    课题的研究背景及进展    1
1.2.1    非接触式电流传感器-电流互感器    1
1.2.2    谐波电流的测量方法    2
1.3    问题的提出和设计目标    3
2    总体方案及测量方法论证    4
2.1    系统总体方案    4
2.2    谐波电流产生及电流互感    4
2.3    基于程控滤波的谐波电流测量    6
2.4    基于FFT分析的谐波电流测量    6
3    系统硬件电路设计    7
3.1    主控制器电路    7
3.2    谐波电流产生电路    8
3.3    无接触式电流传感电路    9
3.4    程控滤波电路    10
3.5    谐波电流的有效值转换电路    10
3.6    谐波电流的峰值测量电路    11
3.7    电压比较电路    12
3.8    高速采样电路    12
4    系统程序设计    14
4.1    基于程控滤波的程序设计    14
4.1.1    FPGA等精度测频    14
4.1.2    STM32主控设计    15
4.2    基于FFT分析的谐波测量程序设计    16
4.2.1    FPGA方案程序总体框架    16
4.2.2    PLL时钟模块    16
4.2.3    AD9226模块    16
4.2.4    FPGA FFT IP核介绍    17
4.2.5    FFT模块    18
4.2.6    RGB显示模块    18
5    实物调试和数据分析    20
5.1    整体系统硬件调试    20
5.2    功率放大电路测试    20
5.3    非接触式电流传感电路测试    21
5.4    基于程控滤波的测量单元测试    22
5.5    基于FFT分析的测量单元测试    24
5.6    分析与结论    25
6    结语    25
参考文献：    26
致谢    28